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F. R. HILL.

FUHNACE.

APPLICATION FILED SEPT. 3. |918.

Patented Spt. 30, 1919.

FRANK n. HILL,

OF KEELER, CALIFORNIA, ASSIGNOR TO WILFRED W. WATTERSON, 0F

BISHOP, CALIFORNIA.

FURNACE.

termes.

Specification of Letters Patent.

Patented Sept. 30, 1919.

Application filed September 3, 1918. Serial No. 252,339.

To all 'Lo/tom t may concern Be it known that I, FRANK R. H1111, a citizen of the United States, residing at Keeler, in the county of Inyo, State of California, have invented new and useful Improvements in Furnaces, of which the following is a specification.

This invention relates particularly to those forms of furnaces used for the reduction of oreI and other materials which may require melting, smelting or fusing, and in which internal combustion takes place; and relates more specifically to furnaces in which soda ash is formed by fusing sodium carbonate or by transforming and fusing sodium bi-carbonate, etc. And in this connection this application is a variation from my case now pending, Serial No. 220,440, filed March 5, 1918, and a further improvement in certain features hereinafter set forth; a fundamental idea therein being to take advantage of the insulating properties of the materials being treated to assist in protecting the interior walls and floor of the furnace and the highly heated portions of the discharge passage against the heat of combustion and the corroding influences of the fused material. In consequence of my improved construction, I am enabled to carry a protecting means against heat and corrosion to a complete accomplishment. Due to the distribution of materials and construction used, I am enabled to offer a very large surface of exposure, and to protect the side walls and discharge passages against the direct corrosive action, as stated above, resulting in a long life for the furnace lining. And I am enabled to concentrate the application of heat to the surface of the treated material and practically confine radiation to the materials being treated, the result being higher fuel efficiency. In addition to the application of air under pressure from above which spreads across and acts as a top stratum under the dome of the furnace as a heat insulating medium, I introduce around the circumference of thel furnace walls, at the base of the top arch, additional air under pressure for combustion which passes through spaces between charging openings of parts and peaks of material formed under same, I find that this latter construction is most effective when admitted or forced into the combustion chamber in a direction some'A what tangential, not radial, which imparts a circular motion to the gases while under combustion.

Figure 1 illustrates a vertical section of an approved form of the furnace being described; Fig. 2 is a plan of same, partly in section.

Material is introduced through chute 10 into an annular charging channel 11 with bottom openings 12 communicating with charging passages (pipes) 13, which permits of uniform and evenly distributed introduction of the material to the interior of the furnace. The feed of material is caused by a revolving` feeder comprising two annular members llywith cross members 11b which act as scrapers; the `whole being movable, by hand or by power, around the annular trough 11. Material within the furnace is indicated at 15; cones of material 15a being the result of the piling of the introduced Inaterial tln'ough the spaced passages 13. These feeding passages 13 are spaced around the entire periphery of the furnace except at the discharge space 16 between walls 17. 15c indicates the position which material of reduction or melted material may occupy in a discharge chamber 16 between retaining walls 17. Air for combustion is admitted through pipe 20 to exterior manifold 21 and discharged by pressure through pipes or passages 22 to the interior of the furnace, in a slightly tangential direction indicated by arrows in Fig. 2, the purpose being to create a gentle whirling motion which assists and improves combustion. Introduction of the air in this manner causes even distribution of the flame and heated gases of combustion over the inverted conical surface of the material; and supplies air all around the furnace walls to keep cool the walls and the outer upper parts of the material pile. Furthermore, by introducing air in this manner, no draft of air is set up over the pile which is strong enough to carry away fine particles of the material. The air pipes 21 also deliver air over the side walls 17 of the discharge outlet, so as to keep these walls cool and prevent or retard their disintegration. 25 is a burner pipe to which liquid fuel and air under pressure are admitted by valves 26 and 27. 28 is a burner head using liquid fuel and air under pressure, throwing out a horizontal flame in ail directions., 30 is an draft is downardand out laterally through the passage 16, the products of combustion passing through the iue 16a. -This action causesthe most highly heated position to be nea-r the bottom of the inverted annular surface of the pile, causing the heat to be drawn downward and creating a center of heat at or near the apex of theI inverted cone formed by the material to be reduced.A

' The'furnace is preferably built in circular formation, with brick side' walls 44 and a dome or arch 45. Brick side walls 44 may be extended/to form the walls of discharge flue or stack 16a; and the whole interior of the furnace, passage 16 and stack 16a may be lined with some refractory Vmaterial as in-V dicated at 46, including a floor lining; and thismaterial maybe either firebriek or may be magnesite in part or in whole. l And the retaining walls 17 may be built of a similar material. However, itis an object of this present improvement to so protect the furnace walls from the high heat and the chemical action of the material at high heat, that the furna'cewalls will not be disintegrated. The bottom surface of floor of the furnace slopes from all` sides toward the center, as is indicated at 5'0 ;v while kthe discharge passage 16has a floor 50- wh-ich slopes downwardly outwardly from the central point of the furnace. Therfurn'ace is built in such proportions that the piled material will occupy a position such as is indicated in the drawings, the walls 17 holding the discharge space 16 open and generally free of the material; and the material stands in an annular pile with its inner invertel conical surface around and under the burner 24; and the foot of thepile comes at the center of the furnace. In this case the center of the floor of the furnace is preferably covered and protected by the foot of the material pile, and some of the material from they foot of the pile extends on down into the passage 16 over the upper part of the floor 50a; so that the central part of the floor directly under the burner, which region is substantially the hottest part of the furnace, is protected by the material. The melted materialv passes off then, as indicated at 15i down the slope of floor 50a over the layer of unmelted material on the iioor and thusquickly passes' out of the zonefof highest temperature. In fact, the action is generally this: That the material, as it rolls down the inner surface of the pile, passes quickly and shortly from the upper zone which is comparatively cool, into a highly heated Zone where it is melted, and then, this melted material flows off over the footing 15, to` theV Y Y outlet tap 40.

I thusV obtain quick discharge of the maV- Y terial from the zone of highestrtemperature; and at the same time I do not have any part of theV furnace or any part of the*Y furnacefloor which is directly exposed to the highest heat of the flame and at'the same time' ex-v posed to the luxing action of the material. It will be Vnoted that the walls 17 at their lowermost points are protected bythe foot of the material pile, and their upper partsY of the furnace construction. This construc-V tion and operation give a very pure soda ash and the furnace has a remarkably longlife y in all parts. Y

Having described a invention, I claim:

1. A furnace' embodying a structure'having-a chamber with an outlet passage, said outlet passage having a floor which slopes downwardly rand outwardly from'the` central part of thechamber floor, means to `feed material to stand in` an annular pile around the central part of the chamber, and means to apply heat to thel inner slopingsurface of the annular pile. Y

2. A furnace embodying a structure having a chamber with a floor sloping from all sides toward a centralpoint, and having a laterally extending outlet with afloor which slopes downwardly and outwardly from the central lowermost point of the furnace floor, means to feed material tostand in an annular pile around the central lowermost point of the furnace Hoor, and means to apply l'ieat to the inner sloping surface of the pile.

3. A furnace embodying a structurehaving a chamber with an outlet passage, said outlet passage having a floor which slopes downwardly and outwardly from Ythe central part of the' chamber floor, side walls forV said outlet extending inwardly into the furnace from the furnace walls' `to Vthe central part of the furnace, means to feed Vmaterial to stand in an annular pile around thecenupper outer edge of the pile and inwardly" over the sloping inner surface.

preferred form of my iso tral part of the chamber, and means to apply 5. In a furnace, a structure having a chamber, means to feed material to stand in an annular pile in the chamber, means to apply heat .to the inner sloping surface of the pile, and means to feed air over the upper outer edge of the pile and inwardly over the sloping inner surface, said material feeding means embodying feed passages spaced around the furnace chamber, and said air feeding means embodying air passages spaced between adjacent material feeding passages.

y6. A furnace embodying a structure having a chamber with an outlet passage, said outlet passage having a floor which slopes downwardly and outwardly from the central part of the chamber floor, side retaining walls for said outlet extending inwardly into the furnace from the furnace wall to the central part of the furnace, means to feed material to stand in an annular ile around the central part of the cham er, means to apply heat to the inner sloping surface of the annular pile, and means to feed air into the furnace chamber over the top of the pile and over the side walls of said outlet. 7. In a furnace, a structure having a chamber, means to feed material to stand in an annular pile in the chamber, means to apply heat to the inner sloping surface of the pile, and means to feed air over the upper outer edge of the pile and inwardly over the sloping inner surface, said air feeding means embodying means to direct the air somewhat tangentially into the chamber to cause a rotary circulation within and over the pile.

8. In a furnace, a structure having a chamber, means to feed material to stand in an annular pile in the chamber, means to apply heat to the inner sloping surface of Copies of this patent may be obtained for the pile, and means to feed air over the upper outer edge of the pile and inwardly over the sloping inner surface, said air feeding means embodying means to direct the air somewhat tangentially into the chamber to cause a rotary circulation within and over the pile, and there being an outlet in the floor of the chamber connected with draft means, so that a spiral downward circulation of the air is maintained over the inner sloping surface of the material pile.

9. In a furnace of the character described, means to feed material to stand in an annular pile in the furnace, a burner adapted to project ame outwardly from a central point toward the inner sloping surface of pile, means to admit air through the roof of the furnace over the burner, means to admit air around the sides of the furnace over the top of the annular pile, and the furnace having a draft opening leading from its central lower portion.

l0. A furnace embodying a structure having a chamber with an outlet passage, said outlet passage having a floor which slopes downwardly and outwardly from the central part of the chamber floor, side walls for said outlet extending inwardly into the furnace from the furnace wall to the central part of the furnace, said outlet passage being open above to the furnace chamber, means to feed material to stand in an annular pile around the central part of the chamber, and means to apply heat to the inner sloping surface of the annular pile.

In witness that I claim the foregoing I have hereunto subscribed my name this 19 day of August, 1918.

FRANK R. HILL.

Witnesses:

A. R. SCHIVELEY, J. S. HENDERSON.

five cents each, by addressing the Commissioner of Patents,

Washington, D. C. 

